The present invention relates to wear resistant composite castings which must have high degree of wear resistance in combination with high ductility and impact strength. Such material can be used to extend significantly the service life of mining and heavy construction equipment such as bucket wheel excavators, dragline excavators, high capacity haulage trucks, and crushing/milling machines.
Hatfield steel and other similar material are used currently in the industry in order to reduce wear of equipment under impact load. These steels have high ductility and plasticity; however, they have relatively low resistance to abrasive and impact wear which reduces the service life of the equipment. Composite castings are also known to be used for protecting the equipment from wear. They usually consist of wear resistant elements and ductile matrix elements which bind the wear resistant elements. In many instances the use of the composite castings replace the Hatfield steel as well as high wear brittle white chromium irons. Such a replacement usually leads to the increase of the service life of the equipment from 2 to 10 times. However, the known composite castings as well as their composition and manufacturing processes have some disadvantages. They are not sufficiently resistant to high dynamic loads. The elevation of the wear resistant elements above the surface of the composite castings and their sharp edges lead to local failure and crack development in the wear resistant elements. The arrangements of the wear resistant elements in parallel rows at an angle relative to the direction of movement of the material leads to the fact that one of the corners of the castings remains unprotected. As a result, the process of continuous wear or "washing out" of the matrix base of the composite casting takes place with the resulting loss of wear resistant elements. The construction and the method of manufacturing lead to the formation of incipient cracks in the matrix base of the castings during the manufacturing process, which reduce the strength of the castings. Finally, the castings are used in hostile environments, they deteriorate due to their low resistance to corrosion. Some castings and methods of their manufacture are disclosed in U.S. Pat. Nos. 3,804,346 and 3,941,589.